The invention relates to a temperature sensor, in particular a high-temperature sensor, having a substrate, at least one resistor structure and at least two connection contacts, wherein the connection contacts electrically contact the resistor structure.
Such temperature sensors are used in the automotive industry to measure the exhaust-gas temperature and/or the combustion temperature of engine gases. Temperature measurement should be carried out as close to the engine as possible. For this reason, these sensors must withstand the high temperatures of the combustion gases. Temperature sensors having a flat resistor structure are known from DE 197 42 696 A1, for example.
A few proposals for the design of such temperature sensors that are stable at high temperatures were made in the prior art. For example, a sensor having a self-supporting cover as protection for a platinum resistor structure was proposed in DE 10 2007 046 900 B4. Document DE 10 2009 007 940 B4 makes known a further high-temperature sensor, in which the substrate contains zirconium oxide. In order to prevent poisoning with ions, which are detrimental to the platinum-layer resistor structure, it is proposed in document DE 10 2011 051 845 B4 to additionally apply sacrificial electrodes onto the substrate.
The aforementioned measures are suitable for the development of a temperature sensor that operates at high temperatures. Due to the use thereof at high temperatures, however, very high temperature gradients often occur during the cooling, in particular, of the temperature sensors. At the same time, increasingly faster reaction times of the temperature sensors are required for engine control and engine regulation. In addition, the temperature sensors should also withstand very high temperatures of up to 1,100° C. without resulting in the destruction or drift of the temperature sensor. Therefore, there is still a need in the art for a temperature sensor which operates reliably at these high temperatures and in the presence of frequently occurring changes in temperature without the measurement of the temperature sensor shifting too extremely and too rapidly over time.
The problem addressed by the invention is therefore that of overcoming the disadvantages of the prior art. In particular, a temperature sensor should operate reliably and for a long period of time at high temperatures, even in the presence of rapid changes in temperature. To this end, the drift of the sensor that occurs during measurement should be held to a minimum.